Cartesian Pipe Facer

ABSTRACT

A facer for use in preparing the opposed ends of polyolefin pipes for fusion into a pipeline has a pair of cutting wheels which rotate in unison. A controller causes the cutting wheels to trace and face the pipe end walls in a closed loop path.

CROSS-REFERENCE TO PENDING APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/029,666, filed Sep. 17, 2013.

BACKGROUND OF INVENTION

This invention relates generally to fusion of polyolefin pipes and moreparticularly concerns facers used to prepare pipe ends for the fusionprocess.

Present facer technology provides hydraulic or electric rotating planarblock facers and single point cutting tools. Known block facerstypically carry one to six blades on opposite faces of the planar block.As they rotate they slowly remove shavings from the pipes to createparallel faces of the pipes to be joined, usually but not always in aplane the perpendicular to the longitudinal axis of the pipes.Typically, the shavings are 0.010″ to 0.030″ thick and continuous alongthe pipe circumference. They pose significant clean up and disposalproblems.

The cutting speed of these facers is limited by the diameter of theblock. The greater their diameter, the less 360° cut rotations they canmake per minute. It is quite common that one inch of pipe length will beremoved during the facing process. At 0.010″ to 0.030″ per rotation,facing time can be quite lengthy. This is of particular concern in pipefusion applications because pipe heating and fusion times are generallyheld within established standards. Therefore, progress in fusionefficiency is substantially limited to reduction of handling or facingtimes.

Non-matching ovalities of the pipes to be joined make efficientachievement of matching surfaces very difficult for block facers. Knownsingle point cutting tools simply do not consistently provide cutfinished surfaces suitable for pipe fusion standards.

It is, therefore, an object of this invention to provide a pipe facerthat can operate at higher cutting speeds than known pipe facers. It isalso an object of this invention to provide a pipe facer that is morelikely to properly face pipes having non-matching ovalities than knownpipe facers. A further object of this invention is to provide a pipefacer that affords greater time efficiency and quality consistency thanknown pipe facers. Another object of this invention is to provide a pipefacer that converts removed pipe material into a form easier to collectand dispose of than known pipe facers.

SUMMARY OF INVENTION

In accordance with the invention, a facer for use in preparing theopposed ends of polyolefin pipes for fusion into a pipeline has a frame,a sled mounted on the frame and responsive to a first servo motor, aboom mounted on the sled and responsive to a second servo motor, a pairof cutting wheels on opposite sides of the boom and responsive to aspindle motor and a controller which coordinates the operation of thefirst and second servo motors and the spindle motor to simultaneouslycause the cutting wheels to trace and face the opposed ends of thepipes. The sled reciprocates along an X-axis in response to the firstservo motor which drives the sled. The boom reciprocates along a Y-axisin response to the second servo motor which drives the boom. The cuttingwheels are spaced-apart, parallel and vertically oriented. They rotatein unison on opposite sides of the boom about a common Z-axis inresponse to the spindle motor which drives the cutting wheels. Thecontroller coordinates the operation of the first and second is servomotors to cause the cutting wheel common Z-axis to trace the center ofthe thickness of the pipe end walls in a closed loop path. Thecontroller simultaneously coordinates the operation of the spindle motorto simultaneously cause the cutting wheels to face the opposed ends ofthe pipes as the closed-loop path is traced.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings in which:

FIG. 1 is a perspective view of a pipe facer;

FIG. 2 is a front elevation view of the pipe facer of FIG. 1;

FIG. 3 is a rear elevation view of the pipe facer of FIG. 1;

FIG. 4 is a left elevation view of the pipe facer of FIG. 1;

FIG. 5 is a right elevation view of the pipe facer of FIG. 1;

FIG. 6 is a top plan view of the pipe facer of FIG. 1;

FIG. 7 is a bottom plan view of the pipe facer of FIG. 1;

FIG. 8 is a perspective view of the carriages of the pipe facer of FIG.1;

FIG. 9 is a cutaway perspective view of the frame and sled of the pipefacer of FIG. 1 showing the horizontal lead nut;

FIG. 10 is a cutaway perspective view of the boom of the pipe facer ofFIG. 1 showing the boom spindle and servo motor shafts;

FIG. 11 is a cutaway perspective view of the boom of the pipe facer ofFIG. 1 showing the vertical lead nut;

FIG. 12 is a perspective view of the vertical lead block of the pipefacer of FIG. 1;

FIG. 13 is a cutaway perspective view of the arbor gear box of the pipefacer of FIG. 1;

FIG. 14 is a cross-sectional view of the arbor gear box of the pipefacer of FIG. 1;

FIG. 15A is a perspective view of the pipe facer of FIG. 1 with thecutting wheels in a “start” position;

FIG. 15B is a perspective view of the pipe facer of FIG. 1 with thecutting wheels in a “12 o'clock” position;

FIG. 15C is a perspective view of the pipe facer of FIG. 1 with thecutting wheels in a “3 o'clock” position;

FIG. 15D is a perspective view of the pipe facer of FIG. 1 with thecutting wheels in a “6 o'clock” position;

FIG. 15E is a perspective view of the pipe facer of FIG. 1 with thecutting wheels in a “9 o'clock” position; and FIG. 16 is a cutawayperspective view of the cable connections of the pipe facer of FIG. 1;

FIG. 17 is an electrical block diagram of the pipe facer of FIG. 1.

While the invention will be described in connection with a preferredembodiment thereof, it will be understood that it is not intended tolimit the invention to that embodiment or to the details of theconstruction or arrangement of parts illustrated in the accompanyingdrawings.

DETAILED DESCRIPTION

Turning to FIGS. 1-7, a facer 10 for use in preparing the opposed endsof polyolefin pipes for fusion into a pipeline has a frame 20, a sled 30mounted on the frame 10 and responsive to a first servo motor 31, a boom40 mounted on the sled 30 and responsive to a second servo motor 47, apair of cutting wheels 77 on opposite sides of the boom 40 andresponsive to a spindle motor 63 and a controller 100 which coordinatesthe operation of the first and second servo motors 31 and 47 and thespindle motor 63 to simultaneously cause the cutting wheels 77 to traceand face the opposed ends T of the pipes.

The Frame

As best seen in FIG. 3, the facer frame 10 as horizontal rails 21mounted between the upper ends of vertical posts 23. The vertical posts23 are adapted for mounting the facer 10 on a stand and/or a fusionmachine (not shown), for example by use of cam rollers 25 on the sidewalls of the posts 23 to engage on guides on the stand or fusion machine(not shown). The horizontal rails 21 act as horizontal linear guideswhich support the horizontal reciprocal motion of four horizontalcarriages 27, seen in FIG. 8.

The Sled

A horizontal servo motor 31 and horizontal servo gearbox 33 drive ahorizontal lead screw 35 which extends between and parallel to the rails21. As best seen in FIG. 9, a horizontal lead nut 37 is threaded on thehorizontal lead screw 35. Continuing to Look at FIG. 9, the horizontallead nut 37 is fixed to the sled 30. The sled 30 is mounted on, andreciprocates with, the horizontal carriages 27 along an X-axis 39 as thehorizontal lead nut 37 advances or retreats in response to the rotationof the horizontal lead screw 35.

The Boom

Turning to FIGS. 10 and 11, the boom 40 is mounted on, and reciprocateshorizontally with, the sled 30. The boom 40 has a vertical frame 41 withvertical rails 43 mounted between the upper and lower ends of thevertical frame 41. The vertical rails 43 act as vertical linear guideswhich support the vertical reciprocal motion of the boom 40 as theyslide in four vertical carriages 45, seen in FIG. 8, on the sled 30.

Returning to FIGS. 10 and 11, a vertical servo motor 47 and verticalservo gearbox 49 drive a vertical lead screw 51 which extends betweenand parallel to the vertical rails 43 and engages a vertical lead nut53, seen in FIG. 12. The vertical lead nut 53 sits between the verticalrails 43 and is threaded on the vertical lead screw 51. The verticallead nut 53 is fixed to the sled 30. The boom 40 reciprocates togetherwith its rails 43 in the vertical carriages 45 along a Y-axis 55 as thevertical lead screw 51 rotates in the vertical lead nut 53. As seen inFIG. 10, the vertical servo motor torque is transmitted to the verticallead screw 51 by a timing belt 57 and two pulleys 59 mounted on a belttension adjustment plate 61.

Continuing to look at FIG. 10, a spindle motor 63 is mounted on top ofthe boom 40. The spindle motor shaft 65 extends inside the boom 40, andtransmits power from the spindle motor 63 to a coupling 67 in an arborgear box 70 at the bottom of the shaft 65.

The Cutters

Turning to FIGS. 13 and 14, the arbor gear box coupling 67 transmitspower from the boom shaft 65 to a vertical pinion shaft 71. A gear train73 transfers the power from the vertical pinion shaft 71 to a horizontalarbor shaft 75. A pair of spaced-apart, axially aligned verticallyoriented cutting wheels 77 rotates in unison, one on each end of thearbor shaft 75, about a common Z-axis 79. The cutting wheels 77 rotatein the same direction and cut in the same direction in response to thespindle motor 63 driving the pair of cutting wheels 77. In someapplications, it may be desirable that the cutting wheels 77counter-rotate. This may be accomplished, for example, by modificationof the gear train 73.

The System Electrical System and Operation

As seen in FIGS. 15A-15E, the system controller 100 coordinates theoperation of the first and second servo motors 31 and 47 to cause thecutting wheel common Z-axis 79 to trace the center of the thickness T ofthe pipe end walls in a closed loop path. In FIG. 15A, the cuttingwheels 77 are at a start position 81 within the circumference of thepipes. In the facing process, they advance to the 12 o'clock position 83shown in FIG. 15B and proceed, as shown but not necessarily, clockwisealong the pipe faces T. FIGS. 15B, 15C, 15D and 15E sequentiallyillustrate the extreme 12, 3, 6, and 9 o'clock positions 83, 85, 87 and89 of the cutting wheels 77, respectively, 12 and 6 o'clock being thehighest and lowest positions of the boom 40 and 3 and 9 o'clock beingclosest and furthest positions of the sled 30 during facing. Thecontroller 80 coordinates the operation of the spindle motor 63 tosimultaneously cause the cutting wheels 77 to face the opposed ends T ofthe pipes as the closed-loop path from 12 o'clock to 12 o'clock istraced.

As seen in FIG. 13, cameras 91 mounted on the boom 40 above the cuttingwheels 77 inspect the faced surfaces T of the pipes after 360° rotationof the cutting wheel assembly along the cross section T of the pipes tobe fused. As seen in FIG. 16, energy chains 93 manage movement of thefacer cables during the facing process.

Turning to FIG. 17, data input 101 by the operator, including the pipeouter diameter (OD) and dimension ratio (DR), is received via a humanmachine interface (HMI) 103 by a programmable logic controller (PLC)105. The HMI 103 provides a graphical interface for the operator andcommunicates via PROFINET to the PLC 105. The PLC 105 is the centralprocess unit (CPU) of the facer 10 and contains the facer operatingprogram. The PLC 105 commands the spindle motor 63 and the servo drives107 and 109 for the X and Y axes 39 and 55. The servo drives 107 and 109control the servo motors 31 and 47, which are the prime movers for the Xand Y axes 39 and 55, in response to an encoder's feedback andcommunicate via PROFINET to the PLC 105. The encoders 111 and 113provide positioning feedback to the servo drives 107 and 109 andcommunicate via PROFINET to the PLC 105. The spindle motor 63 is theprime mover for the facer cutting wheels 77 and is controlled by the CPUthrough digital output.

In operation, the operator enters the pipe OD and DR on the HMI 103. Thedata is stored in the CPU and used to calculate the parameters requiredfor the facing process. When the start facing button on the HMI 103 ispressed, the CPU executes the facing process by sending the requireddata every 150 ms to the servo drives 107 and 109 which control theservo motors 31 and 47 based on their encoder feedback. The CPU alsomonitors and validates the data and, if there is any discrepancy, theprocess is aborted and a fault message is displayed on the HMI 103.

Thus, it is apparent that there has been provided, in accordance withthe invention, a cartesian pipe facer that fully satisfies the objects,aims and advantages set forth above. While the invention has beendescribed in conjunction with a specific embodiment thereof, it isevident that many alternatives, modifications and variations will beapparent to those skilled in the art and in light of the foregoingdescription. Accordingly, it is intended to embrace all suchalternatives, modifications and variations as fall within the spirit ofthe appended claims.

What is claimed is:
 1. For preparing opposed ends of polyolefin pipesfor fusion into a pipeline, a facer comprising a pair of spaced-apartparallel vertically oriented cutting wheels rotatable in unison about acommon axis and a spindle motor driving said pair of cutting wheels.